Search engines serve to locate information both on the World Wide Web and off. For example, search engines search for documents with keywords and return a list of the documents where the keyword was found. Search engines routinely index billions of documents in this manner, which gives users a way to find documents by entering a keyword search query.
However, search engines do not always return the most relevant results in order. A user may enter a search query with a specific intent of the results she wants, but often times the desired documents are not highly ranked. This is typically because a search engine only reads meta-tags or only the first few hundred words of the document text which does not allow accurate result ranking.
While existing search engine technology has proven very useful, there remains ample room for improvement of search engine technology.